For a dawn redwood tree named &#39;Raven&#39;

ABSTRACT

A new and distinct redwood tree named ‘Raven’, characterized by its uniformly symmetrical growth habit, low and uniform branching, deep furrowed and convoluted bark, beautiful disease-resistant, medium green thick foliage, and its outstanding vigor.

LATIN NAME OF THE GENUS AND SPECIES OF THE PLANT CLAIMED

Metasequoia glyptostroboides

VARIETY DENOMINATION

‘Raven’

BACKGROUND OF THE INVENTION

The present invention identifies Metasequoia glyptostroboides ‘Raven’ asa distinct cultivar in the family Taxodiaceae. The novel characteristicsof this cultivar include an extremely uniform pyramidal form with a lowbranching habit, deeply furrowed, convoluted buttressed bark and fastgrowth rate. The convoluted bark gives this tree a distinctive “ancient”appearance. The ‘Raven’ redwood tree exhibits less variation in thesecharacteristics that the common Metasequoia glyptostroboides and retainsthese desirable characteristics through asexual propagation.

The new cultivar ‘Raven’ was noted by Steven D. Cline growing in St.Louis, Mo. as a member of a group of seven redwood trees planted in1952. The ‘Raven’ cultivar is unique amongst these seven trees beingmore uniformly pyramidal in habit at maturity (60 years) and displayingdistinctive and attractive bark patterns with deep, netted convolutionsthat give this cultivar a notable ornamental appearance. In addition,the branching pattern of this cultivar is also distinctive; uniform fromthe lowest branch to the peak both in spiral distribution and verticalspacings around the trunk. These characteristics contrast with speciesand known cultivars of Metasequoia glyptostroboides whose branchingpatterns are more random, less uniform in spacing and with irregularoutline from bottom to the top. The deeply fissured bark of ‘Raven’ isalso notable in contrast to species and other cultivars becoming verydistinctive in this regard extending from the base into the upper canopyto about 20 feet.

SUMMARY OF THE INVENTION

The present invention comprises a new and distinct cultivar of a redwoodtree, botanically known as Metasequoia glyptostroboides and referred toby the cultivar name ‘Raven’. This deciduous conifer tree is growing at4344 Shaw Boulevard, St. Louis, Mo. (38° 36′ 38.58″ N., 90°15′ 30.50″W.).

Metasequoia is an ancient genus dating back to the Lower Pliocene.Living specimens of this fossil genus were discovered in Central Chinain 1941. In 1944, specimens were collected, and in 1945 they were foundto belong to a conifer genus previously unknown in the living flora ofChina. On later expeditions, seeds were collected and distributed toseveral universities, botanical gardens and arboreta, including MissouriBotanical Garden. By 1948, many had germinated, and in 1952, seven treeswere moved to their present location on the east side of the John S.Lehmann building. ‘Raven’ is an exceptional specimen from this grove oftrees.

The ‘Raven’ cultivar is a unique form of Metasequoia glyptostroboideswhose growth habit is extremely uniformly pyramidal (FIG. 2) with a low,uniform branching habit (FIG. 3) and deeply furrowed, convoluted bark(FIG. 4). This convoluted bark gives the tree a very distinctive and“ancient” appearance. The ‘Raven’ dawn redwood has few disease and pestproblems. It exhibits a medium to fast growth rate; up to 3 feet eachyear for established trees. Being a deciduous conifer, the ‘Raven’ dawnredwood has very light/fine foliage that presents very little effort inregard to fall clean up. Therefore, it is not considered a messy treethat would otherwise present maintenance issues for a home landscape. Ittolerates both wet and dry soils. It is hardy to Zone 4 (USDA HardinessZone Map).

As an ornamental specimen, the cultivar ‘Raven’ would be consideredunique for the ornamental market both in terms of distinctive form aswell as rapid growth rate without wood weakness. Presently, few largertrees for the ornamental landscape in today's market provide bothpyramidal shape for use in narrow locations, deciduous foliar characterfor drought tolerance in winter, and tolerance to both dry and wet soilconditions. The cultivar ‘Raven’ has been easily propagated from bothsoftwood and hardwood scion cuttings taken from random areas of themother tree and successfully rooted. The speed of propagation and fastgrowth rate exceeding three feet per year are characteristics which willallow this plant to be marketed widely.

The new ‘Raven’ cultivar has been successfully asexually propagated byrooted hardwood and softwood cuttings taken from various branchlocations on the mother tree. Cuttings (8-10 inches long×¼ inchdiameter) were treated with rooting hormone and placed under mist. Thesecuttings were planted in 2004 and have produced 6-7 foot trees with a2-3 foot spread by 2007 (FIG. 9). These clones are identical to theoriginal plant in all distinguishing characteristics.

Metasquoia glyptostroboides ‘Raven’ exhibits the followingcharacteristics, which in combination, distinguish this cultivarselection from other specimens of Metasequoia glyptostroboides:

1. The ‘Raven’ dawn redwood tree has an extremely uniform pyramidalgrowth habit.2. The ‘Raven’ dawn redwood has a low branching habit with branchesuniformly spaced.3. The ‘Raven’ dawn redwood has deeply furrowed bark, giving the tree avery “ancient” appearance.4. Foliage of ‘Raven’ has few foliar disease problems and is thereforeresistant to disease.5. The ‘Raven’ dawn redwood exhibits remarkable vigor. Once established,the ‘Raven’ dawn redwood grows up to 3 feet each year.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying colored photographs illustrate the appearance and colorof the ‘Raven’ dawn redwood tree. These photographs show the color asaccurately as is reasonably possible to obtain in colored reproductionsof this type. Actual foliage colors may differ slightly due to lightreflectance.

FIG. 1 depicts the ‘Raven’ dawn redwood tree in spring foliage.

FIG. 2 depicts the ‘Raven’ dawn redwood tree in winter foliage and theextremely pyramidal growth form and uniformly spaced branches.

FIG. 3 depicts the low, uniform branching habit and the deeply furrowedand fluted trunk of the ‘Raven’ dawn redwood.

FIG. 4 is a closer image of branching habit, and the deeply furrowed andfluted trunk near the base of the ‘Raven’ dawn redwood.

FIG. 5 is a close-up of the bark of the ‘Raven’ dawn redwood.

FIG. 6 depicts the stem, leaves, and immature female cones.

FIG. 7 depicts the mature female cones.

FIG. 8 depicts the mature male cones.

FIG. 9 asexually scion-cutting propagated tree comes true to form

DETAILED BOTANICAL DESCRIPTION OF THE PLANT

In the following description, color references are made to The RoyalHorticultural Society Colour Chart.

-   Name: Metasquoia glyptostroboides ‘Raven’.-   Market class: deciduous conifer tree.-   Parentage: species.-   Classification: Metasquoia glyptostroboides ‘Raven’.-   Where discovered: in a cultivated area on the grounds of Missouri    Botanical Garden, 4344 Shaw Blvd, St. Louis, Mo. 63110.-   This plant has been asexually reproduced from: rooted hardwood and    softwood ¼″ diameter scion cuttings taken from branches of the    mother plant.-   Present propagation is being done: Albers, Ill.; Elsberry, Mo.; St.    Louis, Mo.-   Form: Tree.-   Shape: Pyramidal.-   Height: 29 meters (95 feet).-   Spread: 15 meters (50 feet).-   Age: 59 years.-   Trunk size: 1.06 meters (42 inches).-   Base: buttressed, to 2.5 m d.b.h.-   Bark: of young trees pale orange-brown with darker flakes and    exfoliating, finally dark reddish brown (RHS 167A) to gray (RHS    197A), fissured.-   Growth rate: fast.-   Strength: excellent.-   Branches:    -   -   Angle of attachment.—branches ascending, 30° (lower portion)            — 45° (middle portion) — 60° (upper portion), branchlets            pendulous.        -   Spacing.—more dense at upper portion relative to lower            portion.        -   Bark.—of young trees pale orange-brown with darker flakes            and exfoliating, finally dark reddish-brown (RHS 167A) to            gray (RHS 197A).-   Stem (non-deciduous branchlet):    -   -   Outer surface.—axis pinkish green or pale purple in first            year, later brownish gray color (165A), smooth in texture;            scale-like leaf occurs spiraled around the branchlet;            lateral branchlets deciduous, opposite, each subtended by            leaflike scale.        -   Lenticels.—none.        -   Buds.—winter buds to 5×3 mm, apex obtuse, scales light            reddish or yellowish brown (165B), ca. 2-2.5×2-2.5 mm            (μ=2.25×2.25 mm).-   Leaves (deciduous branchlet, lateral branchlet): Lateral branchlets    with longer and shorter leaves alternating irregularly, forming an    ovate-elliptic outline 3-7×1.5-4 cm (μ=5×2.75 cm). Leaves borne at    45-60° to branchlet axis, 2-5 mm (μ=3.5 mm) apart.    -   -   Length.—3-7 cm (μ=5 cm).        -   Color.—bluish green or yellowish green adaxially (144B),            paler abaxially, turning orange or red in autumn.        -   Texture (        -   smooth, rought, warty, etc.).—smooth.-   Lamina:    -   -   Length.—0.8-1.5 cm (μ=1.0 cm) on old trees but longer on            younger trees.        -   Width.—1.2-2 mm (μ=1.75 mm).        -   Form.—linear, flattened, pectinately arranged 2-5 mm            (μ=3.5 mm) apart, apex obtuse or with hyaline mucro, more            sharply acute on leaves of leader branchlets.        -   Margin.—smooth.        -   Texture.—upper surface smooth with narrowly grooved midvein,            lower surface bearing obscure lines of stomata, slightly            glaucous.        -   Quantity.—50-60 (μ=55) per branchlet, abundant.        -   Color.—bluish green or yellowish green adaxially, paler            abaxially, turning orange or red in autumn (144B).        -   Ribs and veins.—marginal bands 0.5-0.6 mm (μ=0.55 mm) wide,            narrowly grooved midvein, the midrib slightly raised.-   Pollen cones: Monoecious; male pollen cones ovoid 2.5-5.5×2-3.8 mm    (μ=4×2.9 mm), numerous, decussately arranged on racemes or panicles;    bracts triangular-ovate or obovate, ca. 4×3 mm, lowest minutely    ciliate distally, others glabrous (145A).-   Seed cones: Female seed cones solitary, purplish black when young,    oblong-ellipsoid and to 9×5.5 mm at pollination, subglobose and    1.4-2.5×1.6-2.3 cm (μ=1.95×1.95 cm) when mature; solitary and    pendulous on long stalks of sparsely leaved lateral branchlets;    basal cone scales 9-ovulate, middle 7-ovulate, distal 5-ovulate,    apical sterile; the outer surface of the scale transversely elliptic    or broadly triangular, with a horizontal groove; seeds light brown    (164A), usually obovate, ca. 5×4 mm, with 2 broad, thin, paler    wings; cotyledons usually 2; pollination February-March, before    leaves, seed maturity October-November.-   Has this plant ever been offered for sale: No.

1. A new and distinct cultivar of a redwood tree, Metasequoiaglyptostroboides, named ‘Raven’, as illustrated and described.